Refrigerator gas liquiefier



y 1956 J w. KCHLER REFRIGERATOR LIQUEFIER Filed May 1, 1952 INVENTORJAcoe WILLFWMLAURE s KO ER AA /I/T United States Patent REFRIGERATOR GASLIQUEFIER Jacob Willem Laurens Kiihler, Eindhoven, Netherlands,

assignor to Hartford National Bank and Trust Company, Hartford, Conn.,as trustee Application May 1, 1952, Serial No. 285,440

Claims priority, application Netherlands May 31, 1951 Claims. (Cl.62123) This invention relates to refrigerators comprising two spaceswhich vary continuously in' volume with a substantially constantrelative phase difierence, one space having a lower temperature and theother space a higher temperature, said spaces communicating with oneanother by way of a freezer, a regenerator and a cooler, and containinga gas of invariable chemical composition which traverses a closedthermodynamic cycle whilst being in the same physical state.

Such refrigerators are known and are sometimes referred to asrefrigerators operating on the reversed hotgas engine principle.

It has been proposed by the applicant to'construct a refrigerator in amanner such that a gaseous medium is cooled to 150 C. and is condensed.

It has now been recognized by the applicant that with the same physicalstate, is characterized in that this refrigerator is adapted to condensea gaseous medium, for example air, at at least l50 C., this temperaturebeing reached at one stage by the process which takes place in therefrigerator, the medium condensing on a wall of the freezer throughwhich heat exchange with the working medium takes place and condensationtaking place on at least substantially the whole of that part of thewall which serves for the heat exchange, the freezer being surrounded bya screen having heat-insulating properties and extending substantiallythe whole length of the freezer and the said insulating screen beingseparated from that surface of the freezer which is in heat exchangingcontact with the working medium of the refrigerator by a preferablysubdivided space for the medium to be condensed.

Preferably, the gas pressure of the medium to be condensed differsWithin the screen having heat insulating properties by not more than 0.2atmosphere from atmospheiic pressure. In contradistinction to knownrefrigerators, it is thus not necessary for the liquefaction of gaseousmedia that the gaseous medium should be compressed; this results in aconsiderable advantage.

The medium to be condensed may be supplied to the freezer by means ofthe pressure difference resulting from the difference in temperaturebetween the cooled medium and the medium not yet cooled. As analternative, the medium to be condensed may be supplied to the freezerdue to hydrostatic pressure differences in the condensed medium. Boththese alternatives'permit of other expedients for the supply'of medium,such as fans, being omitted.

Particularly if gas other than air is required to be liquefied it isdesirable that the machine should comprise a discharge pipe for thecondensed medium which pipe contains a liquid-obturation, the dischargepipe being wide enough and having a position before and behind thisliquid-obturation such as to prevent condensed medium from filling theseparts of die pipe at any point.

The invention will now be described with reference to the accompanyingdiagrammatic drawing, given by way of example, in which Fig. 1 shows arefrigerator according to the invention which comprisesa screen havingheat insulating properties,

Fig. 2 shows a modification of the refrigerator shown in Fig. 1,'

Figs. 3 and 4 show a third embodiment of the invention and Fig. 5 showsa fourth embodiment of the invention.

The refrigerator shown in Fig. 1 comprises a cylinder 1 in which adisplacer 2 and a piston 3 reciprocate with a constant phase difference.The displacer 2 and the piston 3 are linked by means of connecting rods4 and 5, respectively, to a crank shaft 6. The space 7 above thedisplacer is the freezing space and communicates via a freezer 8, aregenerator 9 and a cooler 10 with a cooled chamber 11 between thepiston 3 and the displacer 2. The refrigerator is constructed so as toenable very low temperatures to be obtained in one stage from roomtemperature. If, for example, the temperature of the cooled space is +30C., the temperature of the freezing space 7 and of the freezer 8 willbe, for example, C. The freezer 8 comprises a wall 12 through which theheat exchange with a medium to be cooled is required to take place. Thefreezer is surrounded by a screen 13 having heat-insulating properties.The medium to be cooled, for example air, is supplied at the top of thescreen through an aperture 14. This medium condenses on substantiallythe whole of the surface of the wall 12. The pressure of the gas in thespace between the screen 13 and the wall 12 differs by not more than 0.2atmosphere from atmospheric pressure. The medium is fed to the wall as aresult of the pressure difference which occurs by reason of thedifference in temperature between the cooled medium and the mediumnotyet cooled. The freezer comprises at its bottom an annular channel 15 inwhich condensed medium is collected. This condensed mediuniis dischargedby means of a discharge pipe 16. This discharge pipe 16, which has aposition and a width such that the condensed medium cannot fill the pipeat any point, contains a trap working with condensed medium.

This trap is provided with an envelope 17 into which the pipe 16 opens.a container 18 in which the liquid dripped from the pipe 16 iscollected. The container 18 has thus formed in it a trap and thecondensed medium is discharged through the pipe 19. This pipe is wideenough to prevent it from being filled with liquid at any point.

This trap is of particular use of a gas other than air is required to becondensed.

The refrigerator is driven by an electric motor 20 shown in brokenlines.

Fig. 2 shows a freezer of a refrigerator, the heat-insulating screenbeing constructed in a manner slightly different from that of Fig. 1. InFig. 2, parts similar to those of Fig. l are designated by likereference numerals. The Wall 12 of the freezer 8 is provided with fins21. The fins shown extend vertically but as an alternative Arranged tosurround the orifice is it is possible for the fins to be shaped in adifferent form,

for example, in the form of overlapping rings imbricately arranged onthe wall 12 of the freezer. The freezer is surrounded with a cylindricalscreen 22 whichri s open at the top. In thisembodiment, the medium to belique tied is supplied in the same manner as shown in Fig. 1 and thedischarge is also effected in a similar manner. Obviously, the screen22. is not limited to being cylindricalfbut may alternatively tapereither to the one end or to the other..

Fig. 3 shows afreezer with which the channels for the medium. to becondensed are arranged in the body. of the freezer, which comprises awall 30 havinglrecessed into it channels 31 which at their lower endsopen into a. common annular channel 32. This annular channel. 32

comprises a discharge pipe 16. The wall 30 is surrounded by aheat-insulating'screen 33 which at the. top has at 34, flows through theparallel-connected channels 31 and is discharged in a liquidstaterthrough thev channel 16. In this embodiment also, the freezer issurrounded by a screen. having heat-insulating properties and thisscreen and the surface of the freezer which is in heat-,

exchanging contact with the working medium of the machine are separatedby a space provided. for the medium to be condensed.

Fig. 4 is a sectional view taken on the line IV--IV of Fig. 3, WhereasFig. 3 is a sectional view taken on the line III'III of Fig. 4.

Fig. 5 shows a freezer which is constructed as a pipe freezer, thefreezing chamberl. communicating with the regenerator 9-via pipes 40.The pipes 40 are surrounded by a screen 41 having heat-insulatingproperties. 'The medium to be condensed is supplied to the top of thescreen through an aperture 42. At. the bottom provision is made of adischarge pipe 16 by means of which the condensed mediumcan bedischarged. v

' Reference has been. made above to the liquefaction. of air. It will beobvious that the refrigerator may be used for liquefying other gases,for example, nitrogen or argon in which cases the screen will have theadditional advantage that'the condensation process is effected in aspace which excludes the ambient atmosphere. The machine according tothe invention is not limited to being arranged vertically, as shown inthe accompanying drawing, but may alternatively be arranged, forexample, horizontally.

What I claim is: V

1. A refrigerator, comprising a freezer; a regenerator; a cooler and twospaces containing a working medium of invariable chemical compositionwhich traverses .a closed. thermodynamic cycle while being in the samephysical state through. said freezer, ,regeneratorand cooler; one

anapertute 34. The medium to be condensed enters.

space having a relatively lower temperature than the other space; theworking medium in each of said spaces varying continuously in volumewith a substantially constant relative phase difference; a gaseousmedium surrounding said freezer being adapted to condense at least at150 C. on substantially all of the wall of said freezer;-

and a screen having heat insulation properties extending in a spaceconfronting manner for'substantially the whole length of said freezerthereby formingan interspaceforsaid gaseous medium to be condensedtherein.

2. A refrigerator as claimed in claim 1 whereindhe pressure of saidgaseous medium to be condensed within said interspace differs by no morethan 0.2 atmosphere.

from atmospheric pressure.

3. A refrigerator as claimed in. claim 1 wherein the a gaseous medium tobe condensed is supplied to said inter.- space by means of the pressuredifference resulting from the temperature. difference between; thecooled and uncooled. gaseousmcdium; I 1

4. A refrigerator as claimed in claim lJwherein said gaseous mediumto-be condensed is. supplied'tothe freezer by; means of hydrostaticpressure differences in the con,

densed gaseous medium. 1

5 A refrigerator comprising. a freezer; a regenerator;

a cooler and twospaces containing a working medium of invariablechemical composition which traverses a closed thermodynamic cycle whilebeing in the same physical. state through'said freezer, regenerator.and. cooler; one space having a relatively lower temperature thantheother space; the working medium ineach of said spacesv varying;continuously in volume with a substantially constant relativephasediiference; a gaseous medium surrounding said freezer being adaptedto condense at least: at --150 C. err-substantially all' of the wall ofsaid freezer; a screen having heatinsulation properties ex.- tending ina space confronting manner for substantially the whole length of saidfreezer. thereby forming an inter-space for said gaseous medium to becondensed therein; a discharge pipe; and a trap for: the condensedgaseous medium.

References Cited in the file of this patent UNITED STATES PATENTS:

